1. Field of the Invention
The present invention relates generally to the control of a hybrid electric vehicle, and more particularly to a method for detecting torque disturbances in a wheel drive system of a hybrid electric vehicle.
2. Background Art
Previously, hybrid vehicles employed control strategies that sensed a difference in rotational speed between a driven end of a wheelshaft and the wheelshaft's respective wheel to dampen wheel torque oscillations. An example of such a strategy is described in U.S. Pat. No. 6,193,628 assigned to the assignee of the present invention. In the prior art, wheel torque oscillations were dampened by commanding a torque “pulse” that counteracted a torque hole that occurred during automatic transmission upshifts. However, such strategies did not address torque disturbances such as gear backlash that may occur in a hybrid vehicle wheel drive system.